User interface system and method

ABSTRACT

One embodiment of the user interface system comprises: A tactile layer defining a tactile surface touchable by a user and plurality of deformable regions operable between a retracted state, wherein the deformable regions are flush with an undeformable region of the tactile layer; and an expanded state, wherein the deformable regions are proud of the undeformable region. A substrate joined to the undeformable region and defining a fluid port per deformable region and a fluid channel. A displacement device displacing the fluid through the fluid channel and the fluid ports to transition the deformable regions from the retracted state to the expanded state. A first and a second pressure sensor detecting changes in fluid pressure within the fluid due to a force applied to a particular deformable region. A processor determining the particular deformable region to be location of the input force based upon the detected fluid pressure changes.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/405,149, filed 20 Oct. 2010, which is incorporated in its entirety bythis reference.

This application is related to U.S. application Ser. No. 11/969,848filed on 4 Jan. 2008 and entitled “System and Method for Raised TouchScreens”, U.S. application Ser. No. 12/319,334 filed on 5 Jan. 2009 andentitled “User Interface System”, U.S. application Ser. No. 12/497,622filed on 3 Jul. 2009 and entitled “User Interface System”, and U.S.application Ser. No. 13/278,125 filed on 20 Oct. 2011 and entitled “UserInterface System”, which are all incorporated in their entirety by thisreference.

TECHNICAL FIELD

This invention relates generally to touch sensitive user interfaces, andmore specifically to a new and useful system and method for selectivelyraising portions of a touch sensitive display.

BACKGROUND

Touch-sensitive displays (e.g., touch screens) allow users to inputcommands and data directly into a display, which is particularly usefulin various applications. Such touch screen applications include variousconsumer products, including cellular telephones and user interfaces forindustrial process control. Depending on the specific application, thesetouch-sensitive displays are commonly used in devices ranging from smallhandheld PDAs, to medium sized tablet computers, to large industrialimplements.

It is often convenient for a user to input and read data on the samedisplay. Unlike a dedicated input device, such as a keypad with discreteand tactilely distinguishable keys, most touch-sensitive displaysgenerally define a flat and continuous input surface providing nosignificant tactile guidance to the user. Instead, touch-sensitivedisplays rely on visual cues (e.g., displayed images) to guide userinputs.

A serious drawback of touch-sensitive displays is thus the inherentdifficulty a user faces when attempting to input data accurately becauseadjacent buttons are not distinguishable by feel. Improper keystrokesare common, which forces the user to focus both on the keypad (toproperly input the next keystroke) and on the text input line (to checkfor errors); generally, the user is forced to keep his or her eyes onthe display in order to minimize input errors. The importance of tactileguidance is readily apparent in the competition between the Apple'siPhone and RIM's BlackBerry 8800. Touch-sensitive displays and physicalhard buttons each have benefits and drawbacks, and digital devicesgenerally incorporate one such component or the other, although somedevices do include both disparate components, which often makes foreither bulkier devices or devices with less operating power due to sizeconstraints.

As with many touch sensitive displays, nearly any touch on the displaysurface is registered as an input; this substantially prevents the userfrom resting a finger or palm on the touch surface while generatingproper inputs (such as typing). Furthermore, some touch sensitivedisplays rely on capacitance changes due to the presence of a finger ata location on the touch surface to indicate a user input, and thesedevices do not sense user inputs when a barrier exists between a fingerof the user and the touch surface, such as when the user is wearing aglove.

Thus, there is a need in the touch-based interface field to create a newand useful interface that incorporates tactile guidance for one or morecontrol buttons and/or incorporates alternatives to sensing a userinput. This invention provides such an interface and associated method.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 includes an cross-sectional elevation and plan view of the userinterface system of a preferred embodiment of the invention;

FIG. 2 is a cross-sectional elevation view illustrating operation of abutton array in accordance with the preferred embodiment;

FIG. 3 is a cross-sectional view of the tactile layer, substrate, firstpressure sensor, second pressure sensor, displacement device, processor,and display of the preferred embodiment;

FIG. 4 is a cross-sectional elevation view of the deformable region, ofthe preferred embodiment, in the retracted state;

FIG. 5 is a cross-sectional elevation view of the deformable region, ofthe preferred embodiment, in the expanded state;

FIG. 6 is a cross-sectional elevation view of the deformable region, ofthe preferred embodiment, in the user input state;

FIG. 7 is an elevation view of a variation of the fluid channel, of thepreferred embodiment, with a deformable region in the expanded state;

FIG. 8 is a plan view of a variation of the fluid channel, the valve,and the first and second pressure sensors of the preferred embodiment;

FIGS. 9, 10, 11, and 12 are plan and elevation views of, respectively, abutton deformation, a slider deformation, a slider ring deformation, aguide deformation, and a pointing stick deformation of a deformableregion of the preferred embodiment;

FIG. 13 is a plan view of a variation of the user interface system ofthe preferred embodiment of the invention; and

FIG. 14 is a flowchart of the steps of a method of the preferredembodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiments of the inventionis not intended to limit the invention to these preferred embodiments,but rather to enable any person skilled in the art to make and use thisinvention.

1. The User Interface System

As shown in FIG. 1, the user interface system 100 of the preferredembodiment includes: a volume of fluid 110; a tactile layer 120; asubstrate 130; a displacement device 140; a first pressure sensor 150; asecond pressure sensor 160; and a processor 170. The tactile layer 120defines an outer tactile surface 122 touchable by a user and a backsurface 124 opposite the tactile surface 122; the tactile layer 120includes an undeformable region 128 and a plurality of deformableregions 126, wherein the deformable regions 126 are operable between: aretracted state (shown in FIG. 4), wherein the deformable regions 126are substantially flush with the undeformable region 128; and anexpanded state (shown in FIG. 5), wherein the deformable regions 126 aresubstantially proud of the undeformable region 128. The substrate 130 isjoined to the back surface 124 of the undeformable region 128 anddefines at least one fluid port 134 per deformable region 126, and afluid channel 132, wherein the fluid ports 134 communicate the fluid 110between the fluid channel 132 and the back surfaces 124 of thedeformable regions 126. The displacement device 140 displaces a portionof the fluid 110 through the fluid channel 132 and the fluid ports 134to transition the deformable regions 126 from the retracted state to theexpanded state. The first and second pressure sensors 150, 160 detectchanges in fluid pressure within a portion of the fluid 110 due to aninput force applied to the tactile surface 122 at a particulardeformable region 126 (such as in a user input state shown in FIG. 6).The processor 170 determines the particular deformable region 126 to bean input location based upon a comparison of the changes in fluidpressure detected by the first and second pressure sensors 150, 160. Theprocessor 170 may further characterize input forces received at thetactile surface 122 as various input types based upon fluid pressurechange rates, fluid pressure magnitude, or time-dependent changes in thefluid pressure. The substrate 130 may further define a support surface138 that provides a hard stop for the deformable regions 126 of thetactile layer 120 such that a user may not inwardly deform a deformableregion 126 past a certain depth, such as flush with the undeformableregion 128, as shown in FIG. 6. Furthermore, an attachment point 136 mayjoin the tactile layer 120 to the substrate 130 and define a borderbetween a deformable region 126 and an undeformable region 128.

The user interface system 100 may further include one or more of thefollowing: a valve 180; a touch sensor 190; and a display 200. The valve180 may isolate fluid within a single fluid port and deformable regionpair, within a plurality of fluid ports and deformable region pairs, orwithin a portion of the fluid channel 132. The valve 180 preferablyretains a portion of the fluid no at the back surface 124 of at leastone deformable region 126 to maintain the deformable region 126 ineither the expanded state or retracted state. The touch sensor 190preferably detects a user touch 129 on the tactile surface 122, such asat the undeformable region 128. The display 200 preferably outputs animage that is transmitted, through the substrate 130 and the tactilelayer 120, to a user.

The user interface system 100 functions to provide tactile guidance to auser by expanding and retracting the deformable regions 126 to formdistinguishable input regions on the tactile surface 122 of the tactilelayer 120, as described in U.S. patent application Ser. No. 12/497,622titled “User Interface system,” which is incorporated in its entirety byreference. The processor 170 and the first and second pressure sensors150, 160 cooperate to determine the location of an input force 129applied to the tactile surface 122. Specifically, the pressure sensorsand processor 170 cooperate to select, from the plurality of deformableregions 126, the particular deformable region 126 to which the inputforce 129 was applied. The user interface system 100 is preferablyincorporated into an electronic device 210 that includes a digitaldisplay, such as the display of an automotive console, a desktopcomputer, a laptop computer, a tablet computer, a television, a radio, adesk phone, a mobile phone, a PDA, a personal navigation device, apersonal media player, a camera, a gaming console or controller, aremote control, or a watch. Such electronic devices often incorporatetouch sensors and/or touch displays incorporating capacitive, optical,or resistive touch-sensing technology, or possibly other touch-sensingmethods. However, drawbacks may exist in relying on such technology todetect user inputs on deformable tactile surfaces of such electronicdevices. Therefore, detecting user inputs at the deformable regions 126by sensing pressure changes within the fluid 110 used to deform thedeformable regions 126 may be more reliable and/or effective thancurrent touch sensor technology. By coupling each fluid port 134 andassociated deformable region 126 to a central fluid channel 132, thenumber of pressure sensors necessary to isolate the input force locationmay be substantially reduced. In an example of the user interface devicearranged on a display 200 of an electronic device 210, wherein a keypadincluding twenty-six letters is rendered on the display 200, the tactilelayer 120 includes an array of twenty-six deformable regions 126, each aseparate input region aligned with an image of different letter; thedeformable regions 126 are coupled to the single fluid channel 132 viafluid ports 134, and the displacement device 140 expands all of thedeformable regions 126 simultaneously such that the user may tactilelydistinguish between any two input regions (deformable regions 126).Rather than implement twenty-six individual pressure sensors (i.e. onesensor per input region), substantially fewer (e.g., two) pressuresensors detect fluid pressure changes within the fluid channel 132 andthe processor 170 interprets the signals from the pressure sensors toisolate (i.e. determine) a particular deformable region 126 to which theinput force 129 is applied by a user. The tactile layer 120 andsubstrate 130 are preferably substantially transparent such that imageson the display 200 may be viewed by the user. However, the userinterface system 100 may be incorporated into any device in any way toreduce the number of sensors and/or sensor complexity required tocapture a user input on a deformable tactile surface 122.

2. The Volume of Fluid

The volume of fluid 110 of the preferred embodiment functions as themedium by which pressure is conveyed to the deformable regions 126 toexpand or retract the deformable regions 126 and by which forces appliedto the tactile surface 122 are conveyed to the pressure sensors 150,160. The fluid no is preferably a substantially incompressible fluid,but may alternatively be a compressible fluid or any other suitablefluid sustaining a pressure change during operation of the userinterface system 100. The fluid 110 is preferably a liquid (such aswater, glycerin, or ethylene glycol), but may alternatively be a gas(such as air, nitrogen, or argon) or any other substance (such as a gelor aerogel) that expands the deformable region 126 and deforms thetactile surface 122. The fluid 110 preferably substantially fills thefluid ports 134 and the fluid channel 132 and is substantially isolatedfrom other fluids that may be external to the user interface system 100(or the electronic device 210 to which the user interface system 100 isattached), which may reduce the likelihood of air other potentialcontaminants entering and/or creating bubbles within the fluid 110 thatmay disrupt the transmission of an image through the user interfacesystem 100. However, any other suitable type of the fluid 110 may beused.

The volume of fluid is preferably substantially transparent such that animage generated by the display 200 may be transmitted through the fluid110. The volume of fluid 110 also preferably has an index of refractedsubstantially similar to the index of refraction of the substrate 130such that light (e.g., an image) passing through a fluid channel 132(and/or fluid port 134) filled with the fluid 110 is not opticallydistorted by the fluid-fluid channel junction. However, the volume offluid 110 may have any other property.

3. The Tactile Layer and the Deformable Regions

The tactile layer 120 of the preferred embodiment functions to definedeformable regions 126 that serve as input regions providing tactileguidance and receive input forces indicating a user input. The tactilelayer 120 preferably defines the tactile surface 122 that is continuoussuch that, when swiping a finger across the tactile surface 122, theuser does not detect interruptions or seams within the tactile layer120. Specifically, the undeformable region 128 and a deformable region126 preferably comprise a single continuous sheet 220 of materialwithout tactilely distinguishable features between regions.Alternatively, the tactile surface 122 may include featuresdistinguishing one region from another, such as by differing textures,hardness, dimples, or other tactilely distinguishable features. Thetactile surface 122 is also preferably planar; the tactile surface 122may be naturally planar in form or arranged on a surface of thesubstrate 130 that is substantially planar. The tactile layer deformsupon displacement of a portion of the fluid 110 through the fluidchannel 132 and the fluid ports 134 to the back surface 124 of thetactile region at the deformable regions 126; the tactile layer 120 alsopreferably “relaxes” or “un-deforms” back to a normal planar form uponretraction of the portion of the fluid 110, whether actively byreversing flow direction of the displacement device 140 (as shown inFIG. 8) or passively by allowing the elasticity of the tactile surface122 to force fluid back through the fluid ports 134. In one variation,the tactile layer 120 contains a deformable region 126 that is elasticand an undeformable region 128 that is relatively less elastic. Inanother variation, the tactile layer 120 is generally of uniformelasticity throughout at least one cross-section. In yet anothervariation, the tactile layer 120 includes or consists of a smartmaterial, such as Nickel Titanium (“Nitinol”), that has a selectiveand/or variable elasticity. The tactile layer 120 may be of a uniformthickness or varying thickness; for example, the tactile layer 120 maybe thinner at the deformable regions than at the undeformable regionsuch that the deformable regions are more flexible than the undeformableregion.

The tactile layer 120 is preferably optically transparent, but mayalternatively be translucent or opaque. Furthermore, the tactile layer120 preferably has one or more of the following properties: high lighttransmission, low haze, wide viewing angle, minimal internal backreflectance, scratch resistance, chemical resistance, stain resistance,smoothness (e.g., low coefficient of friction), minimal out-gassing,chemical inertness in the presence of the fluid 110, and/or relativelylow rate of degradation when exposed to ultraviolet light. The tactilelayer 120 preferably comprises a suitable elastic material, includingpolymers and silicon-based elastomers such as poly-dimethylsiloxane(PDMS) or RTV Silicon (e.g., RTV Silicon 615). In the variation above inwhich the tactile layer 120 includes distinct elastic and relativelyinelastic portions, the inelastic portion is preferably comprised of apolymer or glass, such as: elastomers; silicon-based organic polymerssuch as poly-dimethylsiloxane (PDMS); thermoset plastics such aspolymethyl methacrylate (PMMA); photocurable solvent-resistantelastomers such as perfluropolyethers; polyethylene terephthalate (PET);or any other suitable material. The tactile layer 120 may, however,comprise any other suitable material.

Each deformable region 126, of the plurality of deformable regions ofthe tactile layer 120, is operable between at least two states,including: a retracted state, wherein the deformable regions 126 aresubstantially flush with the undeformable region 128; and an expandedstate, wherein the deformable regions 126 are substantially proud of theundeformable region 128. However, a deformable region 126 may beoperable in any other state, such as a recessed state, wherein thedeformable region 126 is recessed substantially below the undeformableregion 128. A deformable region 126 in the expanded state may act as:(1) a button that, when pressed by the user, implies a single inputlocation (shown in FIG. 9); (2) a slider that, when pressed, implies aninput locations at multiple inputs along the deformable region 126(shown in FIG. 10); and/or (3) a pointing stick that implies adirectional input (shown in FIG. 11). The deformation of the deformableregion 126 may, however, provide any other suitable input type whereinuser contact at the deformable region 126 affects fluid pressure in aportion of the fluid in a way detectable by at least one of the pressuresensors.

A deformable region 126 that is a button preferably has a dome-likeshape, as shown in FIG. 9, but may alternatively have a cylindrical-likeshape (with a flat top surface), a pyramid-like shape, a cube-like shape(with a flat top), or any other suitable button shape. The pressuresensors 150, 160 preferably recognize a user touch 129 applied to thebutton as a user input.

A deformable region 126 that is a slider preferably has a ridge likeshape, as shown in FIG. 10, but may alternatively have a ring likeshape, as shown in FIG. 11; however, a plus-like shape or any othersuitable slider shape is also possible. The pressure sensors 150, 160preferably recognize user touches 129 at different locations along theslider and distinguish these user touches as different user inputs, suchas a first input type for a swipe along the slider in a first directionand a second input type for a swipe in the opposite direction. In onevariation, the slider is of a ring-like shape and acts like a “clickwheel” similar is form and function to the second-generation Apple iPod,as shown in FIG. 11.

A deformable region 126 that is a pointing stick, like the button,preferably has a dome-like shape, as shown in FIG. 12, but mayalternatively have a cylindrical-like shape (with a flat top surface), apyramid-like shape, a cube-like shape (with a flat top), or any othersuitable button shape. The pressure sensors 150, 160 preferablyrecognize user touches 129 in different directions and/or at differentlocations along the pointing stick and distinguish these user touches asdifferent user inputs. Preferably, depression of the expanded deformableregion 126 that is a pointing stick implies a user input type related tothe location of the depression relative to the geometry of the pointingstick. For example, in the variation in which the deformable region 126is a pointing stick with a dome-like shape, a depression of thedeformable region 126 in the upper right quadrant is interpreteddifferently than a depression thereof in the lower right quadrant.Additionally, the user may depress the deformable region 126 that is apointing stick in a sweeping motion, for example, a “sweep” from theupper right quadrant to the lower right quadrant of the deformableregion 126. This may be interpreted as a dynamic input, such as thoserecognized on the “click wheel” of a second generation Apple iPod. Inanother example, the inputs on a deformable region 126 that is apointing stick may perform in a manner similar to the pointing sticktrademarked by IBM as the TRACKPOINT and by Synaptics as the TOUCHSTYK(which are both informally known as the “nipple”).

4. The Substrate

The substrate 130 of the preferred embodiment functions to support thetactile layer 120 such that fluid 110 communicated through the fluidchannel 132 and the fluid ports 134 outwardly deforms the deformableregions 126. The back surface 124 of the tactile layer 120 is preferablyattached to the substrate 130 via an attachment point 136 (shown inFIGS. 1 and 5) that at least partially defines the size and/or shape ofthe undeformable region 128; the attachment point 136 functions todefine a border between a deformable region 126 and the undeformableregion 128 of the tactile layer 120. The attachment point 136 may be aseries of continuous points that define an edge or boundary, but mayalternatively be a series of non-continuous points; the system may alsocomprise a series of attachment points. The attachment point 136 may beformed via an adhesive, chemical bonding, welding, diffusion bonding, orany other suitable attachment material and/or method. The method and/ormaterial used to form the attachment point 136 preferably yields similaroptical properties as the tactile layer 120 and/or the substrate 130,but may alternatively yield any other optical property. Otherundeformable regions of the tactile layer 120 may or may not be adheredto the substrate 130 using similar or identical materials and/ormethods. However, any other suitable arrangement, material, and/ormanufacturing method may be used to join the substrate 130 to thetactile layer 120. The substrate and tactile layer assembly maytherefore comprise a sheet 220 containing at least the passive elementsnecessary to provide tactile guidance on a surface, such as on a displayof an electronic device 210.

The substrate 130 preferably comprises a substantially rigid materialsuch that a force applied on the tactile surface 122 and transmittedthrough the substrate 130 does not substantially deform any of the fluidports 134 or the fluid channel 132. By substantially maintaining thecross-section of the fluid channel 132 and/or fluid ports 134, the fluidis still preferably communicated throughout the fluid channel 132, fluidports 134, back surfaces 124 of the deformable regions 126, and thepressure sensors 150, 160 such that the pressure sensors and processor170 may reliably generate and interpret fluid pressure signals todetermine the location of a user input on the tactile surface 122. Thesubstrate 130 also preferably defines a substantially rigid supportsurface 138 adjacent to a deformable region 126. The support surface 138of the substrate 130 preferably resists deformation of the deformableregion 126 inward past flush with the undeformable region 128, as shownin FIG. 6. This provides support for the tactile layer 120 tosubstantially prevent the tactile layer 120 from deforming into a fluidport 134 when the force is applied over a deformable region 126. Thesupport surface 138 also preferably provides a hard stop upon which thedeformable region 126 rests in the retracted state, as shown in FIG. 4,such as following active withdrawal of a portion of the fluid from thefluid channel 132 to retract the deformable region 126. The substrate130 is preferably uniform in thickness, though only the side of thesubstrate 130 adjacent to the tactile layer 120 may be planar. Thesupport surface 138 is also preferably planar, but the support surface138 may also define a concave geometry into which the deformable layerdeforms in a third, recessed state. However, the substrate 130 may be ofany other geometry that retains the undeformable region 128 and permitsthe deformable regions 126 to expand to the expanded state and retractto the retracted state.

The substrate 130 also functions to define the fluid channel 132 andfluid ports 134. In a first variation, the substrate 130 comprises afirst sub-layer joined to a second sub-layer, wherein the firstsub-layer includes an elongated pocket and the second sub-layer includesa plurality of through-bores. In this variation, the fluid channel 132is defined by the elongated pocket of the first sub-layer and a surfaceof the second sub-layer adjacent to first sub-layer; the through-boresof the second sub-layer define the fluid ports 134, and the fluid ports134 are preferably aligned with the fluid channel 132 such that thefluid is communicable between the fluid ports 134 and the fluid channel132. In this first variation, the pocket is preferably machined into thesecond sub-layer, such as by laser ablation, bulk micromachining, orconventional machining (e.g., with a keyseat cutter or endmill), but mayalso be etched, formed, molded or otherwise created in the firstsub-layer. The fluid channel 132 is preferably large enough incross-section to communicate the fluid to the fluid ports 134 at asuitable flow rate given a pressure increase generated by thedisplacement device 140; however, the fluid channel 132 is preferablysubstantially small enough in cross-section such that the fluid channel132 is substantially difficult for the user to detect visually; however,the fluid no may have an index of refraction matched substantially tothat of the substrate 130 such that the fluid channel 132 issubstantially difficult for the user to see despite the size of thefluid channel 132. The through-bores are preferably machined into thesecond sub-layer, such as by laser ablation, bulk micromachining, orconventional drilling, but may also be formed, etched, molded, orotherwise created in the second sub-layer. The bores (fluid ports 134)are preferably substantially small in cross-section such that the userdoes not detect the fluid ports 134 through the tactile layer 120,either visually when looking through the tactile layer 120 or tactilelywhen sweeping a finger across the tactile surface 122. For example, thefluid ports 134 may be circular in cross-section and less that 500 um indiameter, though the fluid ports 134 are preferably less than 100 um indiameter. In a second variation, the substrate 130 comprises a firstsub-layer joined to a second sub-layer, wherein the first sub-layerdefines a recess with border substantially encompassing the perimeter ofthe deformable regions 126 and the second sub-layer is substantiallysimilar to the second sub-layer described in the first variation. Inthis second variation, the first and second sub-layers join to enclosethe recess and form a substantially long and wide cavity within thesubstrate 130, wherein the cavity communicates a portion of the fluid tothe fluid ports 134. In the first and second variations above, or in anyother variation, the first and second sub-layer may be joined by anyacceptable means, such as by the materials and/or methods describedabove to join the tactile layer 120 to the substrate 130. In a thirdvariation, the fluid ports 134 are a property of the material; forexample, the substrate 130 may comprise a porous material that includesa series of interconnected cavities that allow the fluid no to flowthrough the substrate 130 to the back surfaces 124 of the deformableregions 126. However, the substrate 130 may comprise any other materialor any number of sub-layers containing any number of features formed byany process, and the sub-layers may be joined (if applicable) in anyother way. Furthermore, the substrate 130 may define any number of fluidports 134, of any shape or size, per deformable region 126.

In the variation of the substrate 130 that defines a substantiallyplanar surface adjacent to the back surface 124 of the tactile layer120, the fluid channel 132 preferably communicates a portion of thefluid no in a direction substantially parallel to the plane of thesubstrate 130. The fluid channel 132 is preferably elongated andpreferably passes through a substantial portion of the substrate 130.Furthermore, the fluid ports 134 preferably communicate the fluid 110 ina direction substantially normal to the planar surface of the substrate130. However, the fluid 110 may pass through the fluid ports 134 andfluid channel 132 in any other direction, such as in a variation of theuser interface system 100 comprising a series of stacked fluid channelsand a network of fluid ports.

The substrate 130 preferably has optical properties substantiallysimilar to the optical properties of the tactile layer 120, such asoptical transparency, low internal reflectance, and low hazecharacteristics. The substrate 130 also preferably has chemicalproperties similar to those of the tactile layer 120, such as minimaloutgassing and chemical inertness in the presence of the fluid 110.

As shown in FIG. 1, the fluid channel 132 couples the displacementdevice 140 to the back surfaces 124 of the deformable regions 126. Thefluid channel 132 allows the fluid 110 to enter the fluid ports 134 toexpand the deformable regions 126. Fluid may also be displaced away fromthe deformable regions 126 through the fluid channel 132 to retract thedeformable regions 126. As shown in FIGS. 3, and 13, in a firstvariation, a deformable region 126 is arranged beside the fluid channel132. In a second variation, as shown in FIG. 7, a deformable region 126is arranged on top of the fluid channel 132; in this second variation,the fluid channel 132 may be of a cross-sectional area substantiallysimilar to that of the fluid port 134, but may alternatively be larger(shown in FIG. 7), smaller (shown in FIG. 2), or of any other suitablesize. The second variation of the arrangement of the fluid channel 132may decrease complexity in the implementation of multiple deformableregions 126. For example, in the first variation, the fluid channel 132may require extended fluid ports 134 that couple the deformable regions126 to the fluid channel 132, as shown in FIG. 13; but, in the secondvariation, the fluid ports 134 may be short and immediately adjacent tothe fluid channel 132, as shown in FIGS. 1, 7, and 8. However, the fluidchannel 132 may be of a single main channel of any suitable form, suchas a zig-zag (FIG. 8), a serpentine (FIG. 1), a loop, a straightchannel, a set of parallel channels, and set of parallel andperpendicular intersecting channels, a set of stacked andnon-intersecting channels of any form.

The fluid channel 132 preferably includes a first end and a second end.In a first variation, the first end is a fluid inlet and a fluid outlet.In this first variation, the second end is preferably closed, or“blind”, such that fluid may neither enter nor exit the fluid channel132 at the second end, as shown in FIG. 1. In a second variation, thefirst end functions as a fluid inlet and the second end functions as afluid outlet, as shown in FIG. 8. In this variation: the fluid channel132 may define a fluid loop within the user interface system 100; and/orthe first and second ends may function as a fluid inlet and a fluidoutlet interchangeably. However, any other suitable arrangement of thefluid channel 132 may be used.

5. The Displacement Device

The displacement device 140 of the preferred embodiment functions todisplace a portion of the fluid 110 within the fluid channel 132 andfluid ports 134 to expand the deformable regions 126 from the retractedstate to the expanded state. The displacement device 140 is preferably amechanical pump (such as micro pump #MDP2205 from ThinXXSMicrotechnology AG of Zweibrucken, Germany or micro pump #mp5 fromBartels Mikrotechnik GmbH of Dortmund, Germany). However, thedisplacement device 140 may alternatively be a plunger-type device, asshown in FIG. 1, a heating element that expands a portion of the fluidno by heating the fluid, or a series of electrodes that displace aportion of the fluid through the fluid ports 134 via electroosmoticflow. However, the displacement device 140 may alternatively influencethe volume of the fluid no in any other suitable manner, for example, asdescribed in U.S. patent application Ser. No. 12/497,622 titled “UserInterface System” or in U.S. patent application Ser. No. 13/278,125titled “User Interface System”, which are both hereby incorporated intheir entirety by this reference. The displacement device 140 ispreferably coupled to the first end of the fluid channel 132, as shownin FIG. 1, but may be coupled to any other section of the fluid channel132. When implemented in a mobile device, such as a cell phone or tabletcomputer, the displacement device 140 preferably increases the volume ofthe fluid no between the substrate 130 and the back surface 124 of thetactile layer 120 at each deformable region 126 by 0.003 ml to 0.1 ml;this volume is preferably suitable to expand a circular deformableregion 126, with a diameter between 2 mm and 10 mm, to an extent tacitlydistinguishable by the user. When implemented in this or any otherapplication, however, the volume of the fluid displaced may be of anyother suitable amount.

6. The First and Second Pressure Sensors

The first and second pressure sensors 150, 160 of the preferredembodiment function to detect a change in fluid pressure within aportion of the fluid no, wherein the pressure change is due to an inputforce 129 applied to and inwardly deforming a particular deformableregion 126. A change in fluid pressure within a portion of the fluid nois preferably communicated to the pressure sensors 150, 160 via alongitudinal pressure wave (e.g., a P-wave) through a portion of thefluid channel 132, a portion of a fluid port 134, or any other fluidconduit within the user interface system 100; however, the pressurechange may be communicated via a transverse wave or combination oflongitudinal and transverse waves. Pressure wave reflections within thefluid channel 132, fluid ports 134, or any other fluid conduit in theuser interface system 100 are also preferably captured by the pressuresensors 150, 160 such that the origin of the pressure wave (e.g., theinput force) can be traced via analysis of the pressure wave data by theprocessor 170.

The first and second pressure sensors 150, 160 are preferably coupled tothe fluid channel 132, wherein the first pressure sensor 150 detectsfluid pressure changes in the fluid channel 132 at a first location andthe second pressure sensor 160 detects fluid pressure changes in thefluid channel 132 at a second location different than the firstlocation, as shown in FIG. 1. The pressure sensors 150, 160 preferablydetect the input force 129 that is applied on a deformable region 126 inthe expanded state, but may also or alternatively detect the input force129 that is applied on a deformable region 126 in the retracted orrecessed states. For example, in the variation in which the substrate130 defines a support surface 138 that is concave, the user may apply aforce 129 to the tactile surface 122 that inwardly deforms a particulardeformable region 126 past flush with the undeformable region 128. Whenthe user applies the input force 129 to the tactile surface 122, thefluid 110 is preferably prevented from escaping the fluid channel 132(e.g., from either end of the fluid channel 132), such as by closing avalve 180 between the fluid channel 132 and displacement device 140 orby locking the position of the displacement device 140. Thus, the inputforce 129 that inwardly deforms the particular deformable region 126also increases fluid pressure at the back surface 124 of the particulardeformable region 126; the increase in fluid pressure is communicatedthrough the associated fluid port 134 (or ports), through the fluidchannel 132, and to the pressure sensors 150, 160.

The pressure sensors 150, 160 may be located adjacent to the backsurface 124 of a deformable region 126, within a fluid port 134, and/orin the fluid channel 132. A portion of either pressure sensor 150 or 160may be arranged within the substrate 130 or may be physicallycoextensive with the substrate 130. For example, the first pressuresensor 150 may include a diaphragm that is physically coextensive withthe substrate 130 and forms a portion of a wall of the fluid channel 132such that a fluid pressure change within the fluid channel 132 deformsthe diaphragm (as shown in FIG. 8); this deformation preferably resultsin an output from the first pressure sensor 150. In this example, thediaphragm may be formed (such as by machining, etching, or molding)directly into the substrate 130. A portion of either pressure sensor 150or 160 may also or alternatively be arranged on or within the tactilelayer 120. For example, the first pressure sensor 150 may comprise astrain gage that is mounted on the back surface 124 of the tactile layer120 at a deformable region 126; a force applied to the deformable region126 in the expanded state produces an output, from the first pressuresensor 150, indicative of a strain at the deformable region 126.Furthermore, the variation of a pressure sensor that comprise a straingauge may indirectly detect a pressure change within the fluid no bycapturing a strain in any portion of the tactile layer 120 and/or thepermeable layer 140. A strain captured by a pressure sensor ispreferably indicative of a change in pressure within a portion of thefluid 110 (e.g., indicating a user touch on a deformable region 126),but such a strain may also be indicative of a user touch elsewhere onthe tactile layer 120; the processor 170 preferably compares strainscaptured by a plurality of strain gauge pressure sensors to determinethe particular location of such a user touch. However, the pressuresensors may be arranged anywhere else within the user interface system100, may interface with any other element in any other way, and may beof any other type of sensor that directly or indirectly indicates achange in pressure within the fluid 110.

In the variation in which the fluid ports 134 communicate a portion ofthe fluid between the plurality of deformable regions 126 and the fluidchannel 132, the pressure sensors are preferably coupled to the fluidchannel 132. For example, the first pressure sensor 150 may be arrangedsubstantially proximal to the first end of the fluid channel 132 and thesecond pressure sensor 160 may be arranged substantially proximal to thesecond end of the fluid channel 132. A third pressure sensor may also becoupled to the fluid channel 132 and arranged between the first andsecond pressure sensors 150, 160. In the variation that includes a valve180 arranged between a fluid port 134 and the fluid channel 132 andwhich closes to prevent fluid flow out of the fluid port 134 and intothe fluid channel 132, either of the first or second pressure sensors150 or 160 is preferably located within the fluid port 134 or adjacentto the back surface 124 of the deformable region 126. A portion of eachpressure sensor 150, 160 is preferably in direct contact with theportion of the fluid no within any of the fluid channel 132 or fluidports 134 or at the back surface 124 of a deformable region 126;however, the pressure sensors 150, 160 may be substantially remote fromthe fluid channel 132 and fluid ports 134 such that the fluid 110 (andthus the fluid pressure and/or a pressure wave) is communicated to thepressure sensors via a fluid duct; such a fluid duct is preferablysmaller in cross-sectional area than either of the fluid channel 132 andthe fluid ports 134. However, the pressure sensors 150, 160 may bearranged at any other location and fluid pressure may be communicated tothe pressure sensors 150, 160 via any other method, feature, or element.

The pressure sensors 150, 160 are preferably absolute pressure sensors,but may alternatively be differential pressure sensors in which thepressure sensors compare the pressure within a portion of the fluid to areference pressure, such as ambient air pressure proximal to the userinterface system 100. In the variation of the first pressure sensor 150that is a differential pressure sensor taking ambient air pressure asthe reference pressure, a feedback control loop between the displacementdevice 140 and the first pressure sensor 150 may be implemented suchthat fluid pressure within the fluid channel 132 is maintainedsubstantially at ambient air pressure; in the retracted state, thispreferably maintains the deformable regions 126 substantially flush withthe undeformable region 128. This may be particularly useful when theuser interface system 100 is taken to higher altitudes: as altitudeincreases, ambient air pressure decreases and the pressure at the backsurface 124 of a deformable region 126 is preferably modified, via thecontrol loop, to compensate for the change in ambient air pressure. Thepressure sensors 150, 160 may be of any type, such as piezoresistivestrain gauge, capacitive, electromagnetic, piezoelectric, optical,potentiometric, resonant, or thermal pressure sensors. The pressuresensors 150, 160 may also comprise or be replaced by flow meters,wherein the flow meters detect fluid flow within the user interfacesystem 100 (e.g., the fluid channel 132 and/or the fluid ports 134) andthe processor 170 analyzes the outputs of the flow meters to determinethe location of an input force on the tactile layer 120. However, anyother suitable arrangement or type of pressure sensor that detects achange in fluid pressure may be used, and the first and second pressuresensors 150, 160 need not be of the same type or form or arranged insimilar ways within the user interface system 100. However, theprocessor 170 may analyze the output of only a single pressure sensor(such as the first pressure sensor iso) to determine the location of theinput force on the tactile layer, such as via a method similar to thatdescribed in “TIME-REVERSAL FOR TEMPORAL COMPRESSION AND SPATIALFOCUSING OF ACOUSTIC WAVES IN ENCLOSURES” by Deborah Berebichez, Ph.D.,Stanford University, 2005, which is incorporated in its entirety by thisreference.

7. The Valve

The user interface system 100 may further comprise a valve 180 operablebetween an open state, wherein the displacement device 140 displaces aportion of the fluid through the valve 180 to transition a deformableregion 126 from the retracted state to the expanded state, as shown inFIG. 8; and a closed state, wherein the valve 180 substantially retainsa portion of the fluid at the back surface 124 of the deformable region126. The valve 180 preferably cooperates with the displacement device140 to direct a portion of the fluid toward the back surface 124 of adeformable region 126 to expand the deformable region 126. In a firstexample, if a first deformable region 126 is to be expanded and a seconddeformable region 126 is to remain retracted, a first valve 180,arranged between the first deformable region 126 and the fluid channel132 (e.g., along an associated fluid port 134), opens to allow a portionof the fluid to the back surface 124 of the first deformable region 126while a second valve, arranged between the second deformable region 126and the fluid channel 132, remains closed to prevent a change in thestate of the second deformable region 126. In a second example, if thestate of a first deformable region 126A is to be independent of a seconddeformable region 126B, a valve 180 may be arranged within the fluidchannel 132 and between a fluid port associated with a first deformableregion 126A and a fluid port associated with a second deformable region126 such that the valve isolates the first deformable region 126A fromthe second deformable region 126B. To maintain a deformable region 126in the expanded state, a valve 180 arranged between the expandeddeformable region 126 and the fluid channel 132 may close to preventfluid flow away from the back surface 124 of the deformable region 126.The valve 180 may be located: within the fluid channel 132, such as toisolate a first group of deformable regions 126 from a second group ofdeformable regions 126 (as shown in FIG. 13); at the first end of thefluid channel 132 to isolate control flow of the fluid between the fluidchannel 132 and the displacement device 140 (as shown in FIG. 8); withina fluid port 134 to isolate a single deformable region 126 from theplurality of deformable regions 126; or at any other location.

The valve 180 may be any suitable type of valve 180, such as a ball,butterfly, check (i.e. one-way), diaphragm, knife, needle, pinch, plug,reed, or spool valve, or any other type of valve. The valve 180 may alsobe integral with the displacement device 140, such as a piston-typedisplacement device relying on a series of valves to control fluid flowtherethrough. The valve 180 may be of any size, but preferably defines afluid gate of cross-sectional area substantially similar to thecross-sectional area of the fluid channel 132, fluid port 134, or otherelement to which the valve 180 is coupled. The valve 180 is alsopreferably electrically activated, such as by inducing a voltagedifferential across two input leads of the valve 180 to open and/orclose the valve 180. The valve 180 is preferably normally in the closedstate, but may also normally be in the open state or in any other state.The valve 180 preferably permits two-way flow but may alternatively be aone-way (e.g., check) valve. In the variation of the valve 180 that is aone-way valve normally permitting flow from a first side to a secondside, the valve 180 may permit reverse fluid flow only given a fluidpressure at the second side substantially greater than the fluidpressure at the first side (or a fluid pressure at the second sidegreater than a given threshold pressure). In this variation, a userinput of a substantially large force may increase pressure within aportion of the fluid no above a level that is not conducive to thesafety or longevity of the user interface system 100 (or the electronicdevice 210 in which the user interface system 100 is implemented); sucha valve 180, with a return threshold pressure, may open, given such highfluid pressure, to reduce fluid pressure within the channel and prolongthe life of the user interface system 100 (or electronic device 210);such a valve may also or alternatively provide a “click” sensation tothe user given an appropriate input in the tactile surface 122. Thissame feature may be implemented without such a one-way valve, such as byactively opening an electromechanical valve given a fluid pressure,detected by either pressure sensor 150 or 160, above a preset fluidpressure threshold. However, any other type of valve 180, number ofvalves, or arrangement of the valve(s) may be implemented in the userinterface system 100.

8. The Display

The user interface system 100 may further comprise a display 200generating an image that is transmitted through the tactile layer 120.The image is preferably aligned with at least one deformable region 126of the plurality of deformable regions. The image preferably providesvisual guidance to the user, such as by indicating the input typeassociated with an input force 129 applied to a particular deformableregion 126. The display 200 is preferably coupled to the substrate 130opposite the tactile surface 122. The display 200 may be joined to thesubstrate 130 via any of the methods or elements described above to jointhe tactile layer 120 to the substrate 130; however, the display 200 mayalso be clamped, suctioned, or statically adhered to the substrate 130,or joined thereto by any other means or method. The display 200 ispreferably a digital display, such as an e-ink, LED, LCD, OLED, orplasma display. The display 200 may also be remote from the userinterface system 100, wherein the image is projected onto and/or throughthe tactile surface 120. However, the display 200 may be any other typeof display that renders an image that may be transmitted to the user viathe substrate 130 and the tactile layer 120.

9. The Touch Sensor

The user interface system 100 may further comprise a touch sensor 190that detects a user touch on the tactile surface 122 of the tactilelayer 120. The touch sensor 190 may be of any form or function describedin U.S. patent application Ser. No. 13/278,125 titled “User InterfaceSystem.” The touch sensor 190 is preferably a capacitive touch sensor190, but may also be an optical or resistive touch sensor 190 orfunction via any other technology. The touch sensor 190 is preferablyphysically coextensive with the display 200, but may also be interposedbetween the display 200 and the substrate 130 or between the substrate130 and the tactile layer 120, or may be physically coextensive, inwhole or in part, with any other element. The touch sensor 190 may alsobe arranged adjacent to the tactile layer 120 opposite the substrate130, such as in the variation of the touch sensor 190 that is an opticaltouch sensor. The touch sensor 190 preferably compliments the pressuresensors 150, 160: the touch sensor 190 preferably detects a user touch129 on the tactile surface 122 at the undeformable region 128 and thepressure sensors 150, 160 detect a user touch at the deformable regions126. However, the touch sensor 190 may serve as the primary detectionmethod for a touch 129 on a deformable region 126, and the pressuresensors 150, 160 may serve a backup or confirmation role in user inputdetection; however, the opposite may also be implemented. The touchsensor 190 may, however, be of any other type, arranged in any otherlocation, and used in any other way to detect a user input 129 on thetactile surface 122.

10. The Processor

The processor 170 of the preferred embodiment functions to determine thelocation of a user input 129 to be at a particular deformable region126. The processor 170 receives signals from the pressure sensorsindicating detected changes in fluid pressure in the fluid channel 132,the fluid ports 134, and/or at the back surface 124 of the tactile layer120 at one or more deformable regions 126. The processor 170 thereforecooperates with the pressure sensors 150, 160 to detect the presence ofa force on the tactile surface 122 and to interpret the force todetermine the input location; the processor 170 may also detect inputmagnitude, input speed, and/or input direction. The processor 170preferably interprets the force based upon the detected pressurechanges, the known locations of the pressure sensors 150, 160, the knownlocations of the deformable regions 126, the known location of an imagerendered on the display 200 and aligned with a deformable region 126,and/or any other suitable information. The processor 170 may alsocommunicate with additional sensors, such as a touch sensor 190 or athird pressure sensor, to determine the location of the user input.

In a first variation, the pressure sensors 150, 160 detect a fluidpressure change and the processor 170 interprets the presence of a userinput 129 based upon the pressure change. The processor 170 preferablycompares the detected pressure change to a pressure change threshold todetermine whether the detected pressure change is indicative of a userinput. By comparing the detected pressure change to the pressure changethreshold, a proper input is preferably distinct from an improper input,such as the case of the user resting a finger or palm on the tactilesurface 122, as action that is not intended to be a proper input. In afirst example, the user unintentionally brushes a finger or palm againsta particular deformable region 126, causing a substantially smallpressure change within the fluid channel 132; this pressure change isdetected by the pressure sensors 150, 160 but is still less than thethreshold pressure change, so the processor 170 does not determine thepressure change to indicate a proper user input. In a second example,the user rests a finger on top of a particular deformable region 126without intending to provide an input (this may be comparable to a userof a traditional keyboard resting a finger on a key withoutsubstantially depressing the key to generate an input); though thiscauses a change in pressure within the fluid channel 132, the detectedpressure change, again, is not determined to be indicative of a properinput when compared against the threshold input pressure. However, ifthe detected pressure change is above the pressure change threshold, theprocessor 170 preferably determines a proper user input event. Thisprovides a benefit over typical touch-sensitive displays (such as thoseutilizing capacitive sensing methods) that are often unable todifferentiate between user touches of varying force (e.g., between aproper input and a user resting a finger on the display 200). Theprocessor 170, therefore, is preferably able to discern between pressurechanges that result from a finger resting on a particular deformableregion 126 and a finger imparting a force resulting in a pressure changethat is a proper input. The processor 170 may also adjust the pressurechange threshold, such as for varying initial fluid pressures (e.g., thedeformable regions 126 are raised to varying initial heights in theexpanded state by adjusting the initial fluid pressure in the fluidchannel 132). However, rather than compare fluid pressure changes (e.g.,the magnitude of fluid pressure changes, the change rate of fluidpressure changes), the processor 170 may compare the absolute detectedfluid pressure to an absolute pressure threshold; the processor 170 mayalso modify this absolute pressure threshold.

The processor 170 of the first variation may compare the length of timethat the detected pressure change (or absolute detected pressure) isabove a pressure change (or absolute pressure) threshold to a timethreshold (or a combination of time and pressure change thresholds). Inan example, the user initiates a user input by touching a particulardeformable region 126 with a finger but changes his mind and quicklyretracts a finger from the particular deformable region 126; thiseffectively “cancels” the input. Thus, if the length of time that theincreased pressure is detected is below the threshold time, then theprocessor 170 preferably determines that a proper input was not providedand the input 129 is ignored. If the length of time that the increasedpressure is detected is above the threshold time, then the processor 170preferably determines the presence of a proper user input. However, theprocessor 170 and the pressure sensors 150, 160 may cooperate todetermine the presence of a user input using any other suitable meansand/or method.

In a second variation, the pressure sensors 150, 160 and the processor170 cooperate to determine the type of a user input. In a first example,the pressure sensors 150, 160 detect the rate change of the fluidpressure in the fluid channel 132, which is proportional to the rate ofthe applied force on the tactile surface 122. The processor 170determines the type of user input based upon the detected fluid pressurechange rate; for example, a first fluid pressure change rate indicates afirst input type and a second fluid pressure change rate less than thefirst fluid pressure change rate indicates a second input type. In ausage scenario, the input indicates a user desire to scroll through adocument: a higher rate of pressure change requests a faster scroll rateand a lower rate of pressure change indicates a slower scroll rate(though this functionality may also be implemented by analyzing themagnitude of the fluid pressure or the magnitude of the change in fluidpressure rather than the fluid pressure change rate). (This usagescenario may also be applied to changing the brightness or contrast ofthe display 200 or the volume or processing speed of the electronicdevice.) In a second example, the pressure sensors 150, 160 detect themagnitude of the fluid pressure and the processor 170 determines themagnitude of the applied force based upon the magnitude of the fluidpressure, which is proportional to the magnitude of the applied force.Either pressure sensor 150 or 160 may thus function as an analog inputfor the electronic device 210, wherein the a varying force applied to adeformable region 126 results in a variable command, such as volume of aspeaker or firing rate of a gun in a computer game. Similar to the firstexample, a first magnitude of fluid pressure change may indicate a firstinput type and a second magnitude of fluid pressure change may indicatea second input type. In a third example, a determined first length oftime of an applied force may indicate a first input type and a secondlength of time of an applied force may indicate a second input type. Ina usage scenario, the electronic device 210 is a camera with autofocuscapability; the user “half-presses” a shutter button that is adeformable region 126, in the expanded state, to initiate autofocus;however, because the force required to “half-press” the button isrelatively small, the detected force is not necessarily indicative of auser desire to initiate autofocus. In this usage scenario, the processor170 determines the desire to initiate autofocus if the force (e.g., thechange in fluid pressure) is detected over a particular period of time;in this usage scenario, the processor 170 may also detect the magnitudeof the applied force (as described in the second example) to distinguishbetween a user desire to initiate the autofocus capability (a firstinput type) and a user desire to take a photo (a second input type). Ina fourth example, the pressure sensors 150, 160 detect the distance bywhich the user inwardly deforms the particular deformable region 126 inthe expanded state. The distance by which the user inwardly deforms theparticular deformable region 126 may be detected by measuring thepressure and/or pressure change that results from the inward deformationof the expanded particular deformable region 126; specifically, theprocessor 170 may determine that a particular pressure and/or pressurechange correlates to a particular distance by which the user inwardlydeforms the particular deformable region 126. However, the processor 170and the pressure sensors 150, 160 may cooperate to determine the type ofuser input by any other suitable method and/or means.

In a third variation, the pressure sensors 150, 160 and the processor170 cooperate to determine the location of the user input. The thirdvariation relies substantially on a fluidic property known in the field,wherein an increase in fluid pressure at a particular point in a fluidvessel (e.g., a fluid channel 132 or fluid port 134) propagatesthroughout the fluid vessel over time. The first pressure sensor 150 andthe second pressure sensor 160 are preferably coupled to the fluidchannel 132 (or other fluid vessel of the user interface system 100) atan appreciable distance from each other, as shown in FIGS. 1 and 8(although the system may incorporate only a single pressure sensor). Achange in fluid pressure (or absolute fluid pressure) is detected as afunction of time at both the first and second pressure sensors 150, 160;the outputs of the first and second pressure sensors 150, 160 arepreferably of the magnitude of the pressure change (or absolutepressure) relative to time, and a comparison of these two outputspreferably results in a determination of the location of the force 129applied to the tactile surface 122 by the user. In a first variation,the first and second pressure sensors 150, 160 are located at differentlocations within a cavity defined by the fluid port 134 and the backsurface 124 of an associated particular deformable region 126; the twopressure sensors 150, 160 and the processor 170 thus cooperate todetermine the location of a user input along the particular deformableregion 126. In a second variation, shown in FIG. 2, the pressure sensors150, 160 are located at different locations within the fluid channel132, such that the pressure sensors 150, 160 and the processor 170cooperate to determine the location of a user input among variousdeformable regions 126 coupled to the fluid channel 132 via a pluralityof fluid ports 134. In a first example, because an increase in pressureat a particular deformable region 126 requires more time to travel tothe more distant of the first and second pressure sensors 150, 160, theprocessor 170 determines the location of a user input to be closer tothe pressure sensor that detects a pressure change of a certainmagnitude in the least amount of time; in this example, the processor170 preferably determines the specific deformable region 126 upon whichthe input force 129 is applied. In a second example, because fluidpressure changes more rapidly at a location nearer the source of thepressure increase, the processor 170 determines that the location of theuser input 129 is nearer to the pressure sensor that detects a higherrate of pressure change. In a third example, because fluid pressure in afluid increases at a faster rate and reaches a higher maximum fluidpressure nearer the origin of the pressure increase, the processor 170determines the location of the user input to be more proximal to thesensor that detects a higher fluid pressure after a particular timefollowing a first detected change in fluid pressure (e.g., theapplication of the input force).

In a fourth variation, the pressure sensors 150, 160 are located withinthe fluid channel 132 and detect fluid pressure changes therein, asshown in FIGS. 2 and 7. The fluid channel 132 is preferably of asubstantially uniform cross-section and of a known length. Additionally,in the variation of the fluid channel 132 shown in FIG. 7 and thechannel arrangement shown in FIG. 1, the volume of fluid 110 within thefluid ports 134 is preferably small relative to the volume of fluid 110contained within the fluid channel 132; the flow of the fluid 110through the fluid channel 132 may thus be substantially unaffected byfluid flow through any of the fluid ports 134. Furthermore, dataincluding the location of the pressure sensors 150, 160 and the lengthof the fluid channel 132 is preferably available to the processor 170such that standard in-tube fluid flow dynamics may be used to determinethe location of a user input 129 provided on a deformable region 126.For example, as a portion of the fluid no is displaced through the fluidchannel 132 as a result of the force 129 applied by the user, the timeat which a change in pressure is detected at the pressure sensors 150,160 and may used to determine where, within the fluid channel 132, thefluid pressure first increases. More specifically, for a fluid of aknown viscosity traveling through a tube of a known cross-section, thetime difference between when a change in pressure is detected by thefirst pressure sensor 150 and when the change in pressure is detected bythe second pressure sensor 160 may be used by the processor 170 topinpoint the location of the initial pressure increase within the fluidchannel 132, such as relative to the first and second pressure sensors150, 160; this location is preferably associated with the location of afluid port 134 and/or the particular deformable region 126 associatedwith the fluid port 134.

In the above variations, the processor 170 preferably interprets dataprovided by the first and second pressure sensors 150, 160 at aparticular time; the processor 170 may determine the location of theuser touch by comparing the data gathered by the first and secondpressure sensors 150, 160. Generally, the processor 170 may compare themagnitude of the pressure change (in the first variation), the magnitudeof the rate of change (in the second variation), the time of thedetected pressure change (in the third and fourth variations), or anyother suitable data detected by the first and second pressure sensors150, 160 and pertinent to determining the location of the user input129. Alternatively, the processor 170 may determine the location of theuser touch 129 by comparing data gathered by the first and secondpressure sensors 150, 160 to a dataset. For example, the dataset may bea table or library of pressure-related readings that indicate thelocation of a pressure increase given particular outputs from the firstand/or second pressure sensors 150, 160; this preferably indicates theparticular deformed region to which the input force 129 is applied. Inthe example arrangement shown in FIG. 2, a user input at a deformableregion 126C preferably results in comparison of pressure readings at thefirst and second sensors 150, 160 that is different than a pressurereading comparison resulting from a user input at a deformable region126B; the processor 170 determines the input based on these comparisons.This method of determining the location of the user input may alsofacilitate determining locations of user inputs that are provided on thetactile surface 122 simultaneously. For example, in the arrangementshown in FIG. 2, simultaneous user inputs provided at deformable region126A and deformable region 126B preferably result in a comparison ofpressure readings (at the first and second pressure sensors 150, 160)that is different than a pressure reading comparison resulting fromsimultaneous user inputs provided at deformable region 126B anddeformable region 126C; both such pressure reading comparisons arepreferably different than the pressure reading comparison resulting froma single user input provided at deformable region 126A. Preferably, eachdeformable region 126 has a distinct input characteristic, such as adistinct time period over which an input force applied on a deformableregion 126 is transmitted, as a fluid pressure change, from thedeformable region 126 to a pressure sensor(s) 150 or 160 in terms oftime differences. This preferably permits determination of multipleinput locations attributed to multiple simultaneous input forces at aplurality of deformable regions 126; specifically, this preferablyallows the processor 170 to resolve multiple input locations at once bylooking at the combination of pressure signals at each sensor 150, 160.Furthermore, the processor 170 may take into account one or moreprevious input force locations and or relevant timing of previous inputforces when determining a more recent input location. The number ofpressure sensors and deformable regions is preferably chosen to ensurethat each deformable region has such a unique characteristic.

In the variation of the deformable region 126 that functions as a slideror a pointing stick, as the user varies the location of the user inputalong the slider or the direction of the input on the pointing stick,the pressure detected by the first and second pressure sensors 150, 160may be compared to a data set that includes pressure readings expectedfor such applied inputs. However, the dataset may include any suitabletype of data against which the processor 170 may: compare data gatheredfrom the pressure sensors 150, 160; and determine the location of a userinput 129 (or a plurality of simultaneous user inputs). This method isparticularly useful in a device in which the specific locations of userinputs on deformable regions must be predicted; in such a device, thepressure sensors 150, 160 may be the only sensors necessary to detectrelevant details (e.g., location and magnitude) of the user input 129,and this preferably decreases the number and complexity of sensors inthe device. However, any number of pressure sensors may be incorporatedinto the user interface system 100 and any other suitable method fordetermining the location of the user input 129 may be used. Theprocessor may also compare the outputs of any number and/or combinationof pressure sensors within the user interface system 100.

The pressure sensors 150, 160 and the processor 170 may also enhance theperformance of the user interface system 100 or the electronic device210 in which the user interface system 100 is implemented. For example,the processor 170 may determine that the detected pressure within thefluid channel 132 is lower than a predetermined threshold (such as formore than a threshold period of time) and may actuate the displacementdevice 140 to displace additional fluid into the fluid channel 132.Alternatively, the pressure sensors 150, 160 may detect the ambient airtemperature; the processor 170 may, in turn, determine that the ambienttemperature has decreased and thus actuate the displacement device 140to displace fluid out of the fluid channel 132 to decrease the fluidpressure within the fluid channel 132 in order to protect the userinterface system 100 from damage, such as from excessive internalpressures. However, the pressure sensors 150, 160 and processor 170 mayalternatively cooperate to perform any other suitable function.

11. The Method

As shown in FIG. 14, the method S100 of the preferred embodimentfunctions to determine an input location on a tactile surface of theuser interface system 100. The steps include: displacing fluid through afluid channel and a series of fluid ports to outwardly deform aplurality of deformable regions of a tactile layer S110; detecting achange in fluid pressure at a first location within the fluid channeldue to an input force applied to the tactile surface at a particulardeformable region S120; detecting a change in fluid pressure at a secondlocation within the fluid channel due to the input force applied to thetactile surface S130; and selecting the particular deformable region,from the plurality of deformable regions, as the input location basedupon a comparison of the changes in fluid pressure detected at the firstand second locations within the fluid channel S140. The step ofdisplacing the fluid through the fluid channel S110 is preferablyperformed by a displacement device, as described above. The steps ofdetecting the fluid pressure changes at the first and second locationswithin the fluid channel S120, S130 are preferably performed by thefirst and second pressure sensors described above. The step of selectingthe particular deformable region S140 is preferably performed, by theprocessor, via the methods describes above.

As a person skilled in the art will recognize from the previous detaileddescription and from the figures and claims, modifications and changescan be made to the preferred embodiments of the invention withoutdeparting from the scope of this invention defined in the followingclaims.

We claim:
 1. A user interface system comprising: a substrate defining afluid channel comprising a first end and a second end, the fluid channelfluidly coupled to a set of cavities between the first end and thesecond end; a tactile layer comprising a tactile surface, a peripheralregion coupled to the substrate, and a set of deformable regionsadjacent the peripheral region, each deformable region in the set ofdeformable regions cooperating with the substrate to define acorresponding cavity in the set of cavities; a displacement deviceconfigured to displace fluid through the fluid channel and into the setof cavities to transition the set of deformable regions from a retractedsetting to an expanded setting, the set of deformable regionssubstantially flush with the peripheral region in the retracted settingand tactilely distinguishable from the peripheral region in the expandedsetting; a first pressure sensor fluidly coupled to the fluid channelproximal the first end; a second pressure sensor fluidly coupled to thefluid channel proximal the second end, the second pressure sensordiscrete from the first pressure sensor; and a processor configured todetermine selection of a particular deformable region in the set ofdeformable regions in the expanded setting based upon a comparison of afirst signal from the first pressure sensor and a second signal from thesecond pressure sensor.
 2. The user interface system of claim 1, whereina portion of the first pressure sensor is arranged within the substrate.3. An electronic device incorporating the user interface system of claim1, wherein the electronic device is selected from the group consistingof an automotive console, a desktop computer, a laptop computer, atablet computer, a television, a radio, a desk phone, a mobile phone, aPDA, a personal navigation device, a personal media player, a camera, agaming console and controller, a remote control, and a watch.
 4. Theuser interface system of claim 1, wherein the first pressure sensoroutputs the first signal corresponding to a fluid pressure changeproximal the first end of the fluid channel, wherein the second pressuresensor outputs the second signal corresponding to a fluid pressurechange proximal the second end of the fluid channel, and wherein theprocessor estimates an origin of a pressure wave within the fluidchannel based on a comparison of the first signal and the second signaland to identify the particular deformable region corresponding to theorigin of the pressure wave.
 5. The user interface system of claim 4,wherein the processor calculates a first fluid pressure change rate inthe first signal and a second fluid pressure change rate in the secondsignal and estimates the origin of the pressure wave within the fluidchannel based on a difference between the first fluid pressure changerate and the second fluid pressure change rate over time.
 6. The userinterface system of claim 1, wherein the processor determines a maximumpressure within the fluid channel based on the first signal,characterizes the input on the particular deformable region as a firstinput type in response to the maximum pressure within the fluid channelthat falls below a threshold pressure, and characterizes the input onthe particular deformable region as a second input type in response tothe maximum pressure within the fluid channel that exceeds the thresholdpressure.
 7. The user interface system of claim 1, wherein the processordetermines a fluid pressure within the fluid channel based on the firstsignal, characterizes the input on the articular deformable region as afirst input type in response to the fluid pressure within the fluidchannel exceeding a threshold fluid pressure for a first period of time,characterizes the input on the particular deformable region as a firstinput type in response to the fluid pressure within the fluid channelexceeding the threshold fluid pressure for a second period of time. 8.The user interface system of claim 1, wherein the displacement device iscoupled to the first end of the fluid channel, and wherein the secondend of the fluid channel is closed.
 9. The user interface system ofclaim 8, further comprising a valve arranged within the fluid channeland operable between an open state and a closed state, the valve in theopen state when the set of deformable regions transition from theretracted setting into the expanded setting, the valve in the closedstate to maintain the set of deformable regions in the expanded setting.10. The user interface system of claim 1, wherein the substrate definesthe fluid channel that comprises a serpentine channel.
 11. The userinterface system of claim 1, wherein the substrate defines a planarsurface adjacent the tactile layer and defines the fluid channel thatcommunicates fluid through the substrate in a direction substantiallyparallel to the planar surface.
 12. The user interface system of claim11, wherein the substrate defines a set of fluid ports, each fluid portconfigured to communicate from the fluid channel into a correspondingcavity in a direction substantially normal to the planar surface. 13.The user interface system of claim 12, wherein the substrate comprises afirst sub-layer joined to a second sub-layer, the first sub-layerdefining an elongated pocket, the second sublayer enclosing theelongated pocket to define the fluid channel and defining a plurality ofthrough-bores intersecting the elongated pocket to define the set offluid ports.
 14. The user interface system of claim 1, wherein the firstpressure sensor is arranged within the substrate.
 15. The user interfacesystem of claim 1, wherein, in the retracted setting, the processorcontrols the displacement device to substantially match a fluid pressurewithin the fluid channel to a measured ambient air pressure.
 16. Theuser interface system of claim 1, further comprising a capacitive touchsensor coupled to the substrate, the processor configured to detect aninput on the peripheral region based on an output of the touch sensor.17. The user interface system of claim 16, wherein the processor isconfigured to detect an input on a deformable region in the set ofdeformable regions in the retracted setting based on an output of thetouch sensor.
 18. The user interface system of claim 1, furthercomprising a display coupled to the substrate opposite the tactile layerand configured to output an image through the substrate and the tactilelayer.
 19. The user interface system of claim 18, wherein the image issubstantially aligned with a deformable region in the set of deformableregions.
 20. The user interface system of claim 18, wherein thesubstrate and the tactile layer are substantially transparent.
 21. Theuser interface system of claim 18, wherein the display is configured tooutput a set of images comprising the image, each image in the set ofimages defining an alphanumeric character and substantially aligned witha corresponding deformable region in the set of deformable regions inthe expanded setting.
 22. The user interface system of claim 1, whereinthe substrate defines a set of support members, each support memberadjacent a corresponding deformable region in the set of deformableregions and configured to limit deformation of the correspondingdeformable region inward toward the substrate.
 23. The user interface ofclaim 22, wherein each support member in the set of support members isconfigured to resist deformation of the corresponding deformable regioninward passed flush with the peripheral region.
 24. A method fordetecting an input into a user interface system, comprising: displacingfluid into a fluid channel to transition a set of deformable regions ofa tactile layer from a retracted setting to an expanded setting, eachdeformable region in the set of deformable regions substantially flushwith a peripheral region in the retracted setting and tactilelydistinguishable from the peripheral region in the expanded setting andcooperating with a substrate to define a corresponding cavity in a setof cavities, each cavity in the set of cavities fluidly coupled to thefluid channel between a first end of the fluid channel and a second endof the fluid channel, and the tactile layer defining the peripheralregion adjacent the set of deformable regions and coupled to thesubstrate; with a first pressure sensor, detecting a first change influid pressure within the fluid channel proximal the first end of thefluid channel; with a second pressure discrete from the first pressuresensor, detecting a second change in fluid pressure within the fluidchannel proximal the second end of the fluid channel; estimating anorigin of a pressure change within the fluid channel based on acomparison of the first change in fluid pressure and the second changein fluid pressure; and correlating the origin of the pressure changewithin the fluid channel with an input on a particular deformableregion, in the set of deformable regions in the expanded setting. 25.The method of claim 24, wherein estimating the origin of the pressurechange within the fluid channel comprises correlating the first changein fluid pressure with a pressure wave moving in a first directionwithin the fluid channel, correlating the second change in fluidpressure with the pressure wave moving in a second direction within thefluid channel, and determining an origin of the pressure wave within thefluid channel based on a detected time of the first pressure wave, adetected time of the second pressure wave, and a dimension of the fluidchannel.
 26. The method of claim 24, wherein detecting the first changein fluid pressure within the fluid channel comprises detecting a fluidpressure change rate proximal the first end of the fluid channel, andfurther comprising correlating the input on the particular deformableregion with a first input type for the fluid pressure change rate thatfalls below a threshold fluid pressure change rate and correlating theinput on the particular deformable region with a second input type forthe fluid pressure change rate that exceeds the threshold fluid pressurechange rate.
 27. The method of claim 24, wherein detecting the firstchange in fluid pressure within the fluid channel comprises detecting amaximum fluid pressure proximal the first end of the fluid channel, andfurther comprising correlating the input on the particular deformableregion with a first input type for a maximum detected fluid pressurewithin the fluid channel that falls below a threshold maximum detectedfluid pressure and correlating the input particular deformable regionwith a second input type for the maximum detected fluid pressure thatexceeds the threshold maximum detected fluid pressure.